For example, the following patent document 1 describes a bottle unit (c) for a puncture repair kit with an extraction cap (b) attached to a mouth portion (a1) of a bottle container (a), as shown in FIG. 8.
The extraction cap (b) for use in the bottle unit (c) includes a cap body (g) including a first flow channel (e) and a second flow channel (f), and an inner lid (h) to simultaneously close the first and second flow channels (e) and (f). The first flow channel (e) is to take in the compressed air from (a) compressor (d) into the bottle container (a). The second flow channel (f) is to sequentially take out the puncture repair liquid and the compressed air from the bottle container (a).
Specifically, the cap body (g) includes a boss portion (g2) extending upward from a bottom surface of a fitting recess portion (g1) to screw thereto the mouth portion (a1) of the bottle container (a). Upper opening portions (e1) and (f1) respectively for the first and second flow channels (e) and (f) communicate with an upper surface of the boss portion (g2). The inner lid (h) integrally includes an inner lid body (ha) to fit to an outer peripheral surface of the boss portion (g2), and a plug shank portion (hb) to fit into the upper opening portion (f1).
The bottle unit (c), prior to use, is subjected to on-vehicle storage with the first and second flow channels (e) and (f) closed by the inner lid (h). At the time of a puncture repair, the extraction cap (b) in this state is to be piped to operate the compressor (d). This allows the compressed air to flow through the first flow channel (e) into the inner lid body (ha), and upon an increase in internal pressure therein, the inner lid (h) is to automatically come off to open the first and second flow channels (e) and (f).
Accordingly, the inner lid (h) needs not to come off during the storage, and needs to easily come off under the compressed air at the time of the puncture repair. It therefore becomes necessary to enhance precision in fitting dimension between the inner lid (h) and the cap body (g) to control with high precision an interlocking force between the inner lid (h) and the cap body (g).
However, the conventional structure requires that both the inner lid body (ha) and the plug shank portion (hb) be subjected to fitting, and hence interlocking variations occur in both. Therefore, still higher precision is needed for the fitting dimension, thus causing a drop in yield rate and an increase in process costs for a product inspection process.
Additionally, the inner lid (h) needs simultaneous release in the fitting of the inner lid body (ha) and the fitting of the plug shank portion (hb). For example, when the plug shank portion (hb) is first about to come off to cause a gap, the compressed air in the inner lid body (ha) leaks from the gap to the second flow channel (f). Consequently, the internal pressure of the inner lid body (ha) stops increasing. On the other hand, when the inner lid body (ha) is first about to come off to cause a gap, the compressed air leaks from the gap into the bottle container (a) and the pressure in the bottle container (a) increases. Consequently, a pressure difference between the inside and outside of the inner lid body (ha) is reduced. As a result, in either case, the inner lid (h) does not separate from the boss portion (g2). Thus, the inner lid body (ha) and the plug shank portion (hb) need to come off simultaneously. That is, it is required to ensure the high precision in the fitting dimension between the inner lid body (ha) and the plug shank portion (hb).